Final answer:
The speed at which a drill or endmill can rotate is limited by material properties, cutting speed, tool material, and cooling lubrication, which are critical in preventing tool wear and material damage.
Step-by-step explanation:
The limiting factor for how fast a drill or endmill can rotate in a particular material is influenced by a myriad of factors, including the material properties, cutting speed, tool material, and cooling lubrication. The material properties such as hardness, toughness, and thermal conductivity dictate the amount of heat and stress the tool and material can withstand. For example, harder materials require slower speeds to prevent tool wear. The cutting speed must be optimized for efficiency and to prevent thermal damage to the tool and material. Moreover, the tool material itself plays a crucial role; tools made from high-speed steel or carbides can withstand higher speeds. Lastly, sufficient cooling and lubrication are required to reduce friction and heat generation at high speeds, as excessive heat can lead to tool degradation or material warping.